1. Field of the Invention
The present invention relates to packet transmission and, particularly, to a system and method for accessing a jitter buffer.
2. Description of the Related Art
When sending voice data across packet networks, such as telephony-over-LAN (ToL) networks, the voice is usually compressed, packetized and finally sent across the network to the destination. When the packets are sent into the network, they are generated at a constant rate. However, due to behavior of the packet network, the even time intervals between the packets are lost as the packets transit the network. This irregularity in packet separation is referred to as “jitter.” Jitter can cause clicks, delays and other annoyances in multimedia transmission, creating overall poor reproduction quality. A jitter buffer is often used to even out the packet separation. A jitter buffer is a FIFO (first in, first out) buffer in which packets leave the buffer at a predetermined, constant rate.
The length of the packets is typically minimized to reduce the delay induced by the packetization. The size of the jitter buffer, in contrast, is typically based on the expected network delay and as such, could be much higher than the size of a single packet. Jitter buffers that are much longer than the packet size result in unnecessary processing power consumption on the endpoints and intermediate switching entities, as well as unnecessary network traffic due to excess overhead.
Thus, conventional systems employing jitter buffers can disadvantageously mismatch the size of the jitter buffer and the length of data packets, resulting in decreased network performance.